u/joerg-krause / upmpdcli - Code / Diff of /src/execmd.h

Diff of /src/execmd.h [eccd38] .. [727302]

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...
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
#ifndef _EXECMD_H_INCLUDED_
#define _EXECMD_H_INCLUDED_



#include <string>
#include <vector>
#include <stack>



/**
 * Callback function object to advise of new data arrival, or just periodic
 * heartbeat if cnt is 0.
 *
 * To interrupt the command, the code using ExecCmd should either
 * raise an exception inside newData() (and catch it in doexec's caller), or
 * call ExecCmd::setKill()
 *
 */
class ExecCmdAdvise {
public:
    virtual ~ExecCmdAdvise() {}
    virtual void newData(int cnt) = 0;
};

/**
 * Callback function object to get more input data. Data has to be provided
 * into the initial input string, set it to empty to signify eof.
 */
class ExecCmdProvide {
public:
    virtual ~ExecCmdProvide() {}
    virtual void newData() = 0;
};

/**
 * Execute command possibly taking both input and output (will do
 * asynchronous io as appropriate for things to work).
 *
 * Input to the command can be provided either once in a parameter to doexec
 * or provided in chunks by setting a callback which will be called to
 * request new data. In this case, the 'input' parameter to doexec may be
 * empty (but not null)
 *
 * Output from the command is normally returned in a single string, but a
 * callback can be set to be called whenever new data arrives, in which case
 * it is permissible to consume the data and erase the string.
 *
 * Note that SIGPIPE should be ignored and SIGCLD blocked when calling doexec,
 * else things might fail randomly. (This is not done inside the class because
 * of concerns with multithreaded programs).
 *
 */
class ExecCmd {
public:
    // Use vfork instead of fork. Our vfork usage is multithread-compatible as
    // far as I can see, but just in case...
    static void useVfork(bool on);



    /**
     * Add/replace environment variable before executing command. This must
     * be called before doexec() to have an effect (possibly multiple
     * times for several variables).
     * @param envassign an environment assignment string ("name=value")
     */
    void putenv(const std::string& envassign);
    void putenv(const std::string& name, const std::string& value);

    /**
     * Try to set a limit on child process vm size. This will use
     * setrlimit() and RLIMIT_AS/VMEM if available. Parameter is in
     * units of 2**10. Must be called before starting the command, default
     * is inherit from parent.
     */
    void setrlimit_as(int mbytes);

    /**
     * Set function objects to call whenever new data is available or on
     * select timeout. The data itself is stored in the output string.
     * Must be set before calling doexec.
     */
    void setAdvise(ExecCmdAdvise *adv);


    /*
     * Set function object to call whenever new data is needed. The
     * data should be stored in the input string. Must be set before
     * calling doexec()
     */
    void setProvide(ExecCmdProvide *p);

    /**
     * Set select timeout in milliseconds. The default is 1 S.
     * This is NOT a time after which an error will occur, but the period of
     * the calls to the advise routine (which normally checks for cancellation).
     */
    void setTimeout(int mS);

    /**
     * Set destination for stderr data. The default is to let it alone (will
     * usually go to the terminal or to wherever the desktop messages go).
     * There is currently no option to put stderr data into a program variable
     * If the parameter can't be opened for writing, the command's
     * stderr will be closed.
     */
    void setStderr(const std::string& stderrFile);

    /**
     * Execute command.
     *
     * Both input and output can be specified, and asynchronous
     * io (select-based) is used to prevent blocking. This will not
     * work if input and output need to be synchronized (ie: Q/A), but
     * works ok for filtering.
     * The function is exception-safe. In case an exception occurs in the
     * advise callback, fds and pids will be cleaned-up properly.
     *
     * @param cmd the program to execute. This must be an absolute file name
     *   or exist in the PATH.
     * @param args the argument vector (NOT including argv[0]).
     * @param input Input to send TO the command.
     * @param output Output FROM the command.
     * @return the exec output status (0 if ok), or -1
     */
    int doexec(const std::string& cmd, const std::vector<std::string>& args,
               const std::string *input = 0,
               std::string *output = 0);

    /** Same as doexec but cmd and args in one vector */
    int doexec1(const std::vector<std::string>& args,
                const std::string *input = 0,
                std::string *output = 0) {
        if (args.empty()) {
            return -1;
        }
        return doexec(args[0],
                      std::vector<std::string>(args.begin() + 1, args.end()),
                      input, output);
    }

    /*
     * The next four methods can be used when a Q/A dialog needs to be
     * performed with the command
     */
    int startExec(const std::string& cmd, const std::vector<std::string>& args,
                  bool has_input, bool has_output);
    int send(const std::string& data);
    int receive(std::string& data, int cnt = -1);

    /** Read line. Will call back periodically to check for cancellation */
    int getline(std::string& data);

    /** Read line. Timeout after timeosecs seconds */
    int getline(std::string& data, int timeosecs);

    int wait();
    /** Wait with WNOHANG set.
    @return true if process exited, false else.
    @param O: status, the wait(2) call's status value */
    bool maybereap(int *status);

    pid_t getChildPid();

    /**
     * Cancel/kill command. This can be called from another thread or
     * from the advise callback, which could also raise an exception
     * to accomplish the same thing. In the owner thread, any I/O loop
     * will exit at the next iteration, and the process will be waited for.


     */
    void setKill();

    /**
     * Get rid of current process (become ready for start). This will signal
     * politely the process to stop, wait a moment, then terminate it. This
     * is a blocking call.
     */
    void zapChild();

    /**
     * Request process termination (SIGTERM or equivalent). This returns
     * immediately
     */
    bool requestChildExit();

    enum ExFlags {EXF_NONE,
                  // Only does anything on windows. Used when starting
                  // a viewer. The default is to hide the window,
                  // because it avoids windows appearing and
                  // disappearing when executing stuff for previewing
                  EXF_SHOWWINDOW = 1,
                 };
    ExecCmd(int flags = 0);
    ~ExecCmd();

    /**
     * Utility routine: check if/where a command is found according to the
     * current PATH (or the specified one
...
     * @param out output: what the command printed
     * @return true if exec status was 0
     */
    static bool backtick(const std::vector<std::string> cmd, std::string& out);

    class Internal;
private:
    Internal *m;





























    /* Copyconst and assignment are private and forbidden */
    ExecCmd(const ExecCmd&) {}
    ExecCmd& operator=(const ExecCmd&) {
        return *this;
    };
};


/**
 * Rexecute self process with the same arguments.
 *
 * Note that there are some limitations:
 *  - argv[0] has to be valid: an executable name which will be found in
 *    the path when exec is called in the initial working directory. This is
 *    by no means guaranteed. The shells do this, but argv[0] could be an
 *    arbitrary string.
 *  - The initial working directory must be found and remain valid.
 *  - We don't try to do anything with fd 0,1,2. If they were changed by the
 *    program, their initial meaning won't be the same as at the moment of the
 *    initial invocation.
 *  - We don't restore the signals. Signals set to be blocked
 *    or ignored by the program will remain ignored even if this was not their
 *    initial state.
 *  - The environment is also not restored.
 *  - Others system aspects ?
 *  - Other program state: application-dependant. Any external cleanup
 *    (temp files etc.) must be performed by the application. ReExec()
 *    duplicates the atexit() function to make this easier, but the
 *    ReExec().atexit() calls must be done explicitely, this is not automatic
 *
 * In short, this is usable in reasonably controlled situations and if there
 * are no security issues involved, but this does not perform miracles.
 */
class ReExec {
public:
    ReExec() {}
    ReExec(int argc, char *argv[]);
    void init(int argc, char *argv[]);
    int atexit(void (*function)(void)) {

        m_atexitfuncs.push(function);
        return 0;
    }
    void reexec();
    const std::string& getreason() {
        return m_reason;
    }
    // Insert new args into the initial argv. idx designates the place
    // before which the new args are inserted (the default of 1
    // inserts after argv[0] which would probably be an appropriate
    // place for additional options)
    void insertArgs(const std::vector<std::string>& args, int idx = 1);

	a/src/execmd.h		b/src/execmd.h
	...		...
15	* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.	15	* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
16	*/	16	*/
17	#ifndef _EXECMD_H_INCLUDED_	17	#ifndef _EXECMD_H_INCLUDED_
18	#define _EXECMD_H_INCLUDED_	18	#define _EXECMD_H_INCLUDED_
19		19
20	#include <signal.h>
21
22	#include <string>	20	#include <string>
23	#include <vector>	21	#include <vector>
24	#include <stack>	22	#include <stack>
25		23
26	#include "netcon.h"
27
28	/**	24	/**
29	* Callback function object to advise of new data arrival, or just periodic	25	* Callback function object to advise of new data arrival, or just periodic
30	* heartbeat if cnt is 0.	26	* heartbeat if cnt is 0.
31	*	27	*
32	* To interrupt the command, the code using ExecCmd should either	28	* To interrupt the command, the code using ExecCmd should either
33	* raise an exception inside newData() (and catch it in doexec's caller), or	29	* raise an exception inside newData() (and catch it in doexec's caller), or
34	* call ExecCmd::setKill()	30	* call ExecCmd::setKill()
35	*	31	*
36	*/	32	*/
37	class ExecCmdAdvise {	33	class ExecCmdAdvise {
38	public:	34	public:
39	virtual ~ExecCmdAdvise() {}	35	virtual ~ExecCmdAdvise() {}
40	virtual void newData(int cnt) = 0;	36	virtual void newData(int cnt) = 0;
41	};	37	};
42		38
43	/**	39	/**
44	* Callback function object to get more input data. Data has to be provided	40	* Callback function object to get more input data. Data has to be provided
45	* in the initial input string, set it to empty to signify eof.	41	* into the initial input string, set it to empty to signify eof.
46	*/	42	*/
47	class ExecCmdProvide {	43	class ExecCmdProvide {
48	public:	44	public:
49	virtual ~ExecCmdProvide() {}	45	virtual ~ExecCmdProvide() {}
50	virtual void newData() = 0;	46	virtual void newData() = 0;
51	};	47	};
52		48
53	/**	49	/**
54	* Execute command possibly taking both input and output (will do	50	* Execute command possibly taking both input and output (will do
55	* asynchronous io as appropriate for things to work).	51	* asynchronous io as appropriate for things to work).
56	*	52	*
57	* Input to the command can be provided either once in a parameter to doexec	53	* Input to the command can be provided either once in a parameter to doexec
58	* or provided in chunks by setting a callback which will be called to	54	* or provided in chunks by setting a callback which will be called to
59	* request new data. In this case, the 'input' parameter to doexec may be	55	* request new data. In this case, the 'input' parameter to doexec may be
60	* empty (but not null)	56	* empty (but not null)
61	*	57	*
62	* Output from the command is normally returned in a single string, but a	58	* Output from the command is normally returned in a single string, but a
63	* callback can be set to be called whenever new data arrives, in which case	59	* callback can be set to be called whenever new data arrives, in which case
64	* it is permissible to consume the data and erase the string.	60	* it is permissible to consume the data and erase the string.
65	*	61	*
66	* Note that SIGPIPE should be ignored and SIGCLD blocked when calling doexec,	62	* Note that SIGPIPE should be ignored and SIGCLD blocked when calling doexec,
67	* else things might fail randomly. (This is not done inside the class because	63	* else things might fail randomly. (This is not done inside the class because
68	* of concerns with multithreaded programs).	64	* of concerns with multithreaded programs).
69	*	65	*
70	*/	66	*/
71	class ExecCmd {	67	class ExecCmd {
72	public:	68	public:
73	// Use vfork instead of fork. This must not be called in a multithreaded	69	// Use vfork instead of fork. Our vfork usage is multithread-compatible as
74	// program.	70	// far as I can see, but just in case...
75	static void useVfork(bool on)	71	static void useVfork(bool on);
76	{	72
77	o_useVfork = on;
78	}
79	/**	73	/**
80	* Add/replace environment variable before executing command. This must	74	* Add/replace environment variable before executing command. This must
81	* be called before doexec() to have an effect (possibly multiple	75	* be called before doexec() to have an effect (possibly multiple
82	* times for several variables).	76	* times for several variables).
83	* @param envassign an environment assignment string ("name=value")	77	* @param envassign an environment assignment string ("name=value")
84	*/	78	*/
85	void putenv(const std::string &envassign);	79	void putenv(const std::string& envassign);
86	void putenv(const std::string &name, const std::string& value);	80	void putenv(const std::string& name, const std::string& value);
87		81
88	/**	82	/**
		83	* Try to set a limit on child process vm size. This will use
		84	* setrlimit() and RLIMIT_AS/VMEM if available. Parameter is in
		85	* units of 2**10. Must be called before starting the command, default
		86	* is inherit from parent.
		87	*/
		88	void setrlimit_as(int mbytes);
		89
		90	/**
89	* Set function objects to call whenever new data is available or on	91	* Set function objects to call whenever new data is available or on
90	* select timeout / whenever new data is needed to send. Must be called	92	* select timeout. The data itself is stored in the output string.
91	* before doexec()	93	* Must be set before calling doexec.
92	*/	94	*/
93	void setAdvise(ExecCmdAdvise *adv) {m_advise = adv;}	95	void setAdvise(ExecCmdAdvise *adv);
94	void setProvide(ExecCmdProvide *p) {m_provide = p;}
95
96	/**	96	/*
		97	* Set function object to call whenever new data is needed. The
		98	* data should be stored in the input string. Must be set before
		99	* calling doexec()
		100	*/
		101	void setProvide(ExecCmdProvide *p);
		102
		103	/**
97	* Set select timeout in milliseconds. The default is 1 S.	104	* Set select timeout in milliseconds. The default is 1 S.
98	* This is NOT a time after which an error will occur, but the period of	105	* This is NOT a time after which an error will occur, but the period of
99	* the calls to the cancellation check routine.	106	* the calls to the advise routine (which normally checks for cancellation).
100	*/	107	*/
101	void setTimeout(int mS) {if (mS > 30) m_timeoutMs = mS;}	108	void setTimeout(int mS);
102		109
103	/**	110	/**
104	* Set destination for stderr data. The default is to let it alone (will	111	* Set destination for stderr data. The default is to let it alone (will
105	* usually go to the terminal or to wherever the desktop messages go).	112	* usually go to the terminal or to wherever the desktop messages go).
106	* There is currently no option to put stderr data into a program variable	113	* There is currently no option to put stderr data into a program variable
107	* If the parameter can't be opened for writing, the command's	114	* If the parameter can't be opened for writing, the command's
108	* stderr will be closed.	115	* stderr will be closed.
109	*/	116	*/
110	void setStderr(const std::string &stderrFile) {m_stderrFile = stderrFile;}	117	void setStderr(const std::string& stderrFile);
111		118
112	/**	119	/**
113	* Execute command.	120	* Execute command.
114	*	121	*
115	* Both input and output can be specified, and asynchronous	122	* Both input and output can be specified, and asynchronous
116	* io (select-based) is used to prevent blocking. This will not	123	* io (select-based) is used to prevent blocking. This will not
117	* work if input and output need to be synchronized (ie: Q/A), but	124	* work if input and output need to be synchronized (ie: Q/A), but
118	* works ok for filtering.	125	* works ok for filtering.
119	* The function is exception-safe. In case an exception occurs in the	126	* The function is exception-safe. In case an exception occurs in the
120	* advise callback, fds and pids will be cleaned-up properly.	127	* advise callback, fds and pids will be cleaned-up properly.
121	*	128	*
122	* @param cmd the program to execute. This must be an absolute file name	129	* @param cmd the program to execute. This must be an absolute file name
123	* or exist in the PATH.	130	* or exist in the PATH.
124	* @param args the argument vector (NOT including argv[0]).	131	* @param args the argument vector (NOT including argv[0]).
125	* @param input Input to send TO the command.	132	* @param input Input to send TO the command.
126	* @param output Output FROM the command.	133	* @param output Output FROM the command.
127	* @return the exec ouput status (0 if ok), or -1	134	* @return the exec output status (0 if ok), or -1
128	*/	135	*/
129	int doexec(const std::string &cmd, const std::vector<std::string>& args,	136	int doexec(const std::string& cmd, const std::vector<std::string>& args,
130	const std::string *input = 0,	137	const std::string *input = 0,
131	std::string *output = 0);	138	std::string *output = 0);
132		139
133	/** Same as doexec but cmd and args in one vector */	140	/** Same as doexec but cmd and args in one vector */
134	int doexec1(const std::vector<std::string>& args,	141	int doexec1(const std::vector<std::string>& args,
135	const std::string *input = 0,	142	const std::string *input = 0,
136	std::string *output = 0) {	143	std::string *output = 0) {
137	if (args.empty())	144	if (args.empty()) {
138	return -1;	145	return -1;
		146	}
139	return doexec(args[0],	147	return doexec(args[0],
140	std::vector<std::string>(args.begin() + 1, args.end()),	148	std::vector<std::string>(args.begin() + 1, args.end()),
141	input, output);	149	input, output);
142	}	150	}
143		151
144	/*	152	/*
145	* The next four methods can be used when a Q/A dialog needs to be	153	* The next four methods can be used when a Q/A dialog needs to be
146	* performed with the command	154	* performed with the command
147	*/	155	*/
148	int startExec(const std::string &cmd, const std::vector<std::string>& args,	156	int startExec(const std::string& cmd, const std::vector<std::string>& args,
149	bool has_input, bool has_output);	157	bool has_input, bool has_output);
150	int send(const std::string& data);	158	int send(const std::string& data);
151	int receive(std::string& data, int cnt = -1);	159	int receive(std::string& data, int cnt = -1);
		160
		161	/** Read line. Will call back periodically to check for cancellation */
		162	int getline(std::string& data);
		163
		164	/** Read line. Timeout after timeosecs seconds */
152	int getline(std::string& data, int timeosecs = -1);	165	int getline(std::string& data, int timeosecs);
		166
153	int wait();	167	int wait();
154	/** Wait with WNOHANG set.	168	/** Wait with WNOHANG set.
155	@return true if process exited, false else.	169	@return true if process exited, false else.
156	@param O: status, the wait(2) call's status value */	170	@param O: status, the wait(2) call's status value */
157	bool maybereap(int *status);	171	bool maybereap(int *status);
158		172
159	pid_t getChildPid() {return m_pid;}	173	pid_t getChildPid();
160		174
161	/**	175	/**
162	* Cancel/kill command. This can be called from another thread or	176	* Cancel/kill command. This can be called from another thread or
163	* from the advise callback, which could also raise an exception to	177	* from the advise callback, which could also raise an exception
164	* accomplish the same thing	178	* to accomplish the same thing. In the owner thread, any I/O loop
165	*/	179	* will exit at the next iteration, and the process will be waited for.
166	void setKill() {m_killRequest = true;}
167
168	/**	180	*/
		181	void setKill();
		182
		183	/**
169	* Get rid of current process (become ready for start).	184	* Get rid of current process (become ready for start). This will signal
		185	* politely the process to stop, wait a moment, then terminate it. This
		186	* is a blocking call.
		187	*/
		188	void zapChild();
		189
170	*/	190	/**
171	void zapChild() {setKill(); (void)wait();}	191	* Request process termination (SIGTERM or equivalent). This returns
		192	* immediately
		193	*/
		194	bool requestChildExit();
172		195
173	ExecCmd()	196	enum ExFlags {EXF_NONE,
174	: m_advise(0), m_provide(0), m_timeoutMs(1000)	197	// Only does anything on windows. Used when starting
175	{	198	// a viewer. The default is to hide the window,
176	reset();	199	// because it avoids windows appearing and
177	}	200	// disappearing when executing stuff for previewing
		201	EXF_SHOWWINDOW = 1,
		202	};
		203	ExecCmd(int flags = 0);
178	~ExecCmd();	204	~ExecCmd();
179		205
180	/**	206	/**
181	* Utility routine: check if/where a command is found according to the	207	* Utility routine: check if/where a command is found according to the
182	* current PATH (or the specified one	208	* current PATH (or the specified one
	...		...
193	* @param out output: what the command printed	219	* @param out output: what the command printed
194	* @return true if exec status was 0	220	* @return true if exec status was 0
195	*/	221	*/
196	static bool backtick(const std::vector<std::string> cmd, std::string& out);	222	static bool backtick(const std::vector<std::string> cmd, std::string& out);
197		223
198	friend class ExecCmdRsrc;	224	class Internal;
199	private:	225	private:
200	static bool o_useVfork;	226	Internal *m;
201
202	std::vector<std::string> m_env;
203	ExecCmdAdvise *m_advise;
204	ExecCmdProvide *m_provide;
205	bool m_killRequest;
206	int m_timeoutMs;
207	std::string m_stderrFile;
208	// Pipe for data going to the command
209	int m_pipein[2];
210	NetconP m_tocmd;
211	// Pipe for data coming out
212	int m_pipeout[2];
213	NetconP m_fromcmd;
214	// Subprocess id
215	pid_t m_pid;
216	// Saved sigmask
217	sigset_t m_blkcld;
218
219	// Reset internal state indicators. Any resources should have been
220	// previously freed
221	void reset() {
222	m_killRequest = false;
223	m_pipein[0] = m_pipein[1] = m_pipeout[0] = m_pipeout[1] = -1;
224	m_pid = -1;
225	sigemptyset(&m_blkcld);
226	}
227	// Child process code
228	inline void dochild(const std::string &cmd, const char **argv,
229	const char **envv, bool has_input, bool has_output);
230	/* Copyconst and assignment private and forbidden */	227	/* Copyconst and assignment are private and forbidden */
231	ExecCmd(const ExecCmd &) {}	228	ExecCmd(const ExecCmd&) {}
232	ExecCmd& operator=(const ExecCmd &) {return *this;};	229	ExecCmd& operator=(const ExecCmd&) {
		230	return *this;
		231	};
233	};	232	};
234		233
235		234
236	/**	235	/**
237	* Rexecute self process with the same arguments.	236	* Rexecute self process with the same arguments.
238	*	237	*
239	* Note that there are some limitations:	238	* Note that there are some limitations:
240	* - argv[0] has to be valid: an executable name which will be found in	239	* - argv[0] has to be valid: an executable name which will be found in
241	* the path when exec is called in the initial working directory. This is	240	* the path when exec is called in the initial working directory. This is
242	* by no means guaranteed. The shells do this, but argv[0] could be an	241	* by no means guaranteed. The shells do this, but argv[0] could be an
243	* arbitrary string.	242	* arbitrary string.
244	* - The initial working directory must be found and remain valid.	243	* - The initial working directory must be found and remain valid.
245	* - We don't try to do anything with fd 0,1,2. If they were changed by the	244	* - We don't try to do anything with fd 0,1,2. If they were changed by the
246	* program, their initial meaning won't be the same as at the moment of the	245	* program, their initial meaning won't be the same as at the moment of the
247	* initial invocation.	246	* initial invocation.
248	* - We don't restore the signals. Signals set to be blocked	247	* - We don't restore the signals. Signals set to be blocked
249	* or ignored by the program will remain ignored even if this was not their	248	* or ignored by the program will remain ignored even if this was not their
250	* initial state.	249	* initial state.
251	* - The environment is also not restored.	250	* - The environment is also not restored.
252	* - Others system aspects ?	251	* - Others system aspects ?
253	* - Other program state: application-dependant. Any external cleanup	252	* - Other program state: application-dependant. Any external cleanup
254	* (temp files etc.) must be performed by the application. ReExec()	253	* (temp files etc.) must be performed by the application. ReExec()
255	* duplicates the atexit() function to make this easier, but the	254	* duplicates the atexit() function to make this easier, but the
256	* ReExec().atexit() calls must be done explicitely, this is not automatic	255	* ReExec().atexit() calls must be done explicitely, this is not automatic
257	*	256	*
258	* In short, this is usable in reasonably controlled situations and if there	257	* In short, this is usable in reasonably controlled situations and if there
259	* are no security issues involved, but this does not perform miracles.	258	* are no security issues involved, but this does not perform miracles.
260	*/	259	*/
261	class ReExec {	260	class ReExec {
262	public:	261	public:
263	ReExec() {}	262	ReExec() {}
264	ReExec(int argc, char *argv[]);	263	ReExec(int argc, char *argv[]);
265	void init(int argc, char *argv[]);	264	void init(int argc, char *argv[]);
266	int atexit(void (*function)(void))	265	int atexit(void (*function)(void)) {
267	{
268	m_atexitfuncs.push(function);	266	m_atexitfuncs.push(function);
269	return 0;	267	return 0;
270	}	268	}
271	void reexec();	269	void reexec();
272	const std::string& getreason() {return m_reason;}	270	const std::string& getreason() {
		271	return m_reason;
		272	}
273	// Insert new args into the initial argv. idx designates the place	273	// Insert new args into the initial argv. idx designates the place
274	// before which the new args are inserted (the default of 1	274	// before which the new args are inserted (the default of 1
275	// inserts after argv[0] which would probably be an appropriate	275	// inserts after argv[0] which would probably be an appropriate
276	// place for additional options)	276	// place for additional options)
277	void insertArgs(const std::vector<std::string>& args, int idx = 1);	277	void insertArgs(const std::vector<std::string>& args, int idx = 1);